Creaseproofing cellulose textiles with glucose-ureide formaldehyde condensation product



Patented May 13, 1952 CREASEPRUOFING CELLULOSE TEXTILES WITH GLUCOSE-UREIDE FORMALDE- HYDE CONDENSATION PRODUCT Hendrik W. Meijer, Veendam, Netherlands No Drawing. Application January 12, 1949, Se-- rial No. 70,585. In the Netherlands February 3 Claims.

My invention relates to a process for treatin cellulosic material, as well as to the material thus treated.

The following come into consideration as cellulosic material: rayon, linen, jute, flax, hemp, cotton, paper, cardboard and the like. The material may be in the form of fibres, threads, yarns, fabrics, lengths, sheets, shaped articles and the like. It may also consist wholly or partly of regenerated cellulose.

It is an object of my invention to obtain noncreasing or practically non-creasing and/or unshrinkable or practically unshrinkable textiles. Applied to paper, cardboard, paper bags and the like, the process according to my invention imparts thereto surprisingly great strength in wet condition, i. e. when wetted with water it entirely or almost entirely retains its original strength.

Rayon fabrics in particular have the disadvantage of being easily creased, while the same disadvantage also occurs with other cellulosic material, such as linen and cotton. According to a known process the creasability of yarns or fabrics is decreased by impregnating them with incompletely condensed synthetic resin solutions in such a way that the latter are distributed only in the fibres themselves and not to an appreciable extent in the interstices between the fibres after which the resin is hardened by heating to such a degree that the separately impregnated fibres become elastic.

I In the textile industry, therefore, various watersoluble synthetic resins are used. Not only is the fabric weighted thereby, but it also becomes crease-resisting asa result of the increased elasticity. This applies particularly to fabrics and yarns of rayon. An important modification of this known process consists in the soaking of the cellulosic material directly with a solution of the monomeric resin components and the subsequent poly-condensation, in acid medium, to form insoluble resin in the fibre.

The process according to my invention is of the last-mentioned kind, and consists in the cellulosic material being treated, in the presence of aldehydes or compounds forming aldehydes during the treatment, at a pH less than 2.0, with a solution of nitrogen-containing reaction products formed with liberation of water from aldoses or ketoses with at least four carbon atoms in the molecule and organic compounds containing at least one NH: group and either at least one other NHz group or at least a mono-substituted NI-Iz group.

The said nitrogen-containing reaction products can be obtained by reaction of the said aldoses or ketoses in the presence of a dehydrating agent a 2 with the organic compounds containing at least one NH: group and either at least one other NH: group or at least a mono-substituted NH: group.

If, for instance, glucose is used, a nitrogencontaining reaction product of the following formula is obtained:

NHR 0%0 O-CELCHzOH NH-CH CHOH HO O-GHOH or in a simpler form:

NHR

in which R represents hydrogen, an alkyl-, aryl-, or an alkyl-aryl group and G represents the glucosyl radical. Examples of suitable aldoses and ketoses are hexoses, such as glucose, galactose, mannose and fructose. One may also start from polysaccharides, which hydrolyse under the reaction conditions to hexoses, such as cane sugar or maltose.

Examples of organic compounds containingat least one free NH2 group and at least one unsubstituted or mono-substituted NI-Iz group are urea, thiourea and guanidine, as well as their alkyl-, aryl-, or alkyl-aryl derivatives monosubstituted in an NHz group, such as methyland butyl-urea, and substituted or unsubstituted melamines and diamides.

My invention will further be explained with reference to the treatment of cellulosic material with glucose-ureide and formaldehyde in acid medium, but as appears from the above, it is by no means restricted thereto. Glucose-ureide can add one equivalent formaldehyde. Methylol-glucose-ureide is then formed, with the following formula:

This compound is formed by a condensation in weak alkaline medium which is known in itself. It was found that in a weak acid medium the addition product is even formed instantaneously at room temperature. Even in a very strong acid medium no polycondensation to a water-insoluble compound can occur, and also not in the presence of a great excess of formaldehyde, for example an at least five-fold molar excess, as is preferably applied according to my invention.

If, however, cellulosic material is introduced into such a solution at a pH of 2 and is dried after pressing out at elevated temperature, e. g. 90 C., combination with the fibre will take place by the formation of methyl-glucose-ureide bridges between two cellulose chains. These bridges are formed by reaction of the formaldehyde with reactive NH groups of the methylglucose-ureide on the one hand and with hydroxy groups of the cellulose chains on the other hand; in other words, the hydrogen atoms which are connected to nitrogen will be replaced by hyv droxy-methyl groups, whereafter the hydroxymethyl groups thus formed form bridges with the hydroxy groups of the cellulose, water being split off according to the following schematic representation, in which -R- represents the cellulose chain:

This reaction occurs under conditions of low pH and high temperature, while in the absence of the cellulosic material no polycondensation of the methyl-glucose-ureide would take place.

The treatment should be carried out at a low pH (2 or less) to accomplish a reaction with the cellulose chains. 7 The pH used is preferably between 1 and 2. It can be obtained by the addition of strong acids, but according to a further feature of my invention itis preferred to establish the low pH gradually during the treatment by means of compounds, such as ammonium salts of strong acids, which bring about the required low pH during the, treatment by reaction with aldehydes, such as formaldehyde. The bath should adjust itself to this low pH. very slowly, which can beensured by the addition of a bufferas compound such as triethanolamine. The re? quired low pH value can also be obtained by the addition of compounds such as monochloroacetamide, beta-chlorohydrocinnamic acid, whichrrelease the required quantityof acid upon heating. Formaldehyde and glyoxal are suitable aldehydes.

instead of aldehydes, compounds forming aldehydes during the treatment can also be used. Para-formaldehyde and methyl acetamide are examples of such compounds.

The following examples show how the, process of; my inventionmay be carried into effect:

E mple I' 1 .0, ra o pur glu ose-am de isdissol'veda room temperature in400 cos. of an aque us, 40% formaldehyde solution. 5 grams of molten carbowax-1500 (polyethylene glycol) is then added as wetting agent to the solution thus obtained, after which the mixture is diluted with 400 cos. of water and finally a solution of 10 grams of ammonium chloride in 80 grams of water is added.

A rayon fabric is passed at room temperature through the solution thus obtained and is squeezed "out to a 100 percent wet pick-up and isthendriedforl0nr1inutes'at-90 C. at a pH of about 2. The fabric is subsequently washed for one minute at'70 C., to remove free formaldehyde and'further chemicals, with an aqueous solution of 011 per cent-of soap and 0.1 per cent of soda. After rinsing with lukewarm water for some-minutes,'the fabric is dried below 100 C.

The fabric thus obtained is practically uncreasable after 24 hours conditioning, does not shr-lnlo'when washed and has increased 13' per 4 cent in weight, which increase, as well as the uncreasability itself, is permanent to washing.

Example II 120 grams of pure glucose-ureide is dissolved at room temperature in 400 cos. of an aqueous 40 formaldehyde solution. The mixture is then diluted with 3100 ccs. of water, whereupon a solution of 10 grams. of ammonium chloride in grams of water is added. A piece of paper was immersed in this solution for a few seconds and subsequently squeezed out to a per cent wet pick-up, after which it was dried for 3 minutes, at 90 C. at a pH of 2.5. The paper thus obtained has increased 3 per cent in weight, and has a much greater strength in the wet condition than before the treatment and a greater resistance to folding.

InPrinciple the treatment of paperflbre can be applied in the beater, to the wet web ofpaper formed, as well as to the finished paper.

Example III A solution was prepared as in Example I. b t with this difference: that instead of grams of pure glucose-ureide, grams of a clear syrup, obtained by condensation of can sugar with urea, was used.

A rayon fabricwas treated with this solution in the manner described at a pH =,2'.0,whereby the same results were obtained.

I claim as my invention:

l. A process for chemically fixing onto. cellulose fibers a ureide selected from the group con-, sisting of the ureides of the methylol-ketoses, and methylol-aldoses, which comprises treating. the cellulose fibers at a pH between 1 and 2 with the said ureide in the presenceof a member selected from the groupconsisting of formaldehyde and formaldehyde-yielding compounds, at a temper ature of about 90 C. whereby the resultant chemical linkage with the cellulosev is permanent and fast. to washing.

2. A process for chemically fixing, methylolglucose ureide onto cellulose fibers, which comprises treating the latter at a pH between 1 and 2 with the said ureide in, the presence of free'forme aldehyde ata temperature. of about 90 0., whereby theresultant chemical linkage. with the. cellulose is permanent to washing.

3. A process for chemically fixing the ureide of methyl'olated cane sugar onto cellulose fibers,

which, comprises treating the latter at a pH between 1 and 2 with thesaidureiderin thepresence, of free, formaldehyde atv a temperature of about 90 0., whereby the resultant chemical linkage with thecellulose is permanent-to. wash,- ing.

HENDRIK W. MEIJER.

REFERENCES CITED.

The followingreferences are of record in the file, of this patent:

UNITED STATES PATENTS 

1. A PROCESS FOR CHEMICALLY FIXING ONTO CELLULOSE FIBERS A UREIDE SELECTED FROM THE GROUP CONSISTING OF THE UREDES OF THE METHYLOL-KETOSES AND METHYLOL-ALDOSES WHICH COMPRISES TREATING THE CELLULOSE FIBERS AT A PH BETWEEN 1 AND 2 WITH THE SAID UREIDE IN THE PRESENCE OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF FORMALDEHYDE AND FORMALDEHYDE-YIELDING COMPOUNDS, AT A TEMPERATURE OF ABOUT 90* C. WHEREBY THE RESULTANT CHEMICAL LINKAGE WITH THE CELLULOSE IS PERMANENT AND FAST TO WASHING. 